解方程的二分法 matlab 程序

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解方程的二分法  matlab 程序  （ x^3-3*x^2+6*x-1=0）
2 H9 O2 _5 n% N; |# ^
/ f* I5 |4 ^) F% Bisection.m
: q% c3 p: y" w# d& bfunction[k,x,f_value]=Bisection(f,a,b,eps1,eps2,N)
fprintf('k ,a ,b ,x, f\n')
1 p5 h) R7 B9 _; M' `7 G& Tfor k=1:N
    x=(a+b)/2;
    f_value=f(x);
+ w2 n' s6 W* K& h) a1 Y: ?    fprintf( '%3d, %10.9f, %10.9f, %10.9f,%10.9f,\n'...
      ,k ,a ,b ,x, f_value)
    if abs(f_value)< eps1||0.5*(b-a)<eps2
    return
; v* N% X/ Z9 n' _    else
% N' F* P5 V% Q1 A        if f(x)*f(a)<0
          b=x;
& R( E5 ]% }) ~, z4 D        else
          a=x;
1 }* O9 z4 C$ ~        end
        if k== N
1 @! ^3 K, _. R: o          warning ('算法超出最大迭代數!')   
        end
    end

: ~% M' a# S- N1 p7 ~% examlpe7.m
a=0; b=1;
( E' b! |- Z. C( K5 v, H- E5 Seps1=1e-4;eps2=1e-4;
N=300;
f=@ (x) (x^3-3*x^2+6*x-1);
Hfun=@Bisection;
( [. ~# Y* w+ G' K* L[k,x,f_value]= feval(Hfun, f,a,b,eps1,eps2,N);

運行結果
>> examlpe7
k ,a ,b ,x, f
  1, 0.000000000, 1.000000000, 0.500000000,1.375000000,
  k9 G0 P1 I5 K  2, 0.000000000, 0.500000000, 0.250000000,0.328125000,
  3, 0.000000000, 0.250000000, 0.125000000,-0.294921875,
; k' P5 w/ z( c  4, 0.125000000, 0.250000000, 0.187500000,0.026123047,
  5, 0.125000000, 0.187500000, 0.156250000,-0.131927490,
  6, 0.156250000, 0.187500000, 0.171875000,-0.052295685,
  7, 0.171875000, 0.187500000, 0.179687500,-0.012936115,
: C2 _3 ]% ]! u& k0 o- E  8, 0.179687500, 0.187500000, 0.183593750,0.006630838,
. `% b% C2 E" G  `8 R6 p5 A: P7 n  9, 0.179687500, 0.183593750, 0.181640625,-0.003143273,
$ C5 G: `5 `: ]/ H# d1 l+ m 10, 0.181640625, 0.183593750, 0.182617188,0.001746121,
11, 0.181640625, 0.182617188, 0.182128906,-0.000697991,
( @5 z' A' a+ M; I$ ^8 _ 12, 0.182128906, 0.182617188, 0.182373047,0.000524211,
; L0 o$ @/ F, T4 v0 S8 S- i 13, 0.182128906, 0.182373047, 0.182250977,-0.000086854,

& ?6 {) d, G/ G* e* _